1. Technical Field
Several aspects of the present invention relate to a wiring substrate, a method of manufacturing a wiring substrate, and an electronic apparatus, and in particular to a method of manufacturing a wiring substrate for a display and an electronic apparatus equipped with the wiring substrate.
2. Related Art
In recent years, a flexible electronic apparatus has attracted attention. For example, a flexible display provided with airy portability, shock absorbability, and flexibility of hand fitting has a potential to be an electronic apparatus playing a role in the ubiquitous computing society.
As a manufacturing method of the flexible display, a method is known in which a plurality of circuit components is previously formed on a separate substrate (a transfer source substrate) using thin film transistors (TFT) and so on, and then a flexible substrate and the transfer source substrate are disposed facing each other and are pressurized, thereby transferring a plurality of circuit components on the flexible circuit at a time (see, e.g., JP-A-2003-297974).
The circuit components are fixed, for example, face-down (with the terminals facing the substrate side) on the flexible substrate via anisotropic conductive adhesives. The anisotropic conductive adhesive has conductive particles dispersed in an adhesive (a binder), and by pressurizing the circuit element to forcedly spread the binder and thus pinching at least one conductive particle between the circuit element and an electrode of the flexible substrate, electrical connection and mechanical junction of the circuit element can be obtained. Therefore, in the case in which a plurality of circuit elements is transferred at a time, it is required to apply desired pressure evenly to every circuit element.
However, in the case in which a peripheral circuit in the periphery of a pixel area is transferred, for example, in the condition with no pixel circuit formed in the pixel area occupying a majority of the substrate, when the substrates facing each other are pressurized, there are some cases in which the both substrates have a contact with each other in the pixel area. In this case, the pressure to be applied to the connection section is released to prevent the necessary pressure from being applied to the peripheral circuit, and thus a problem arises that the electrical connection in the peripheral circuit can hardly be obtained.
Even in the case in which the peripheral circuit and the wiring on the substrate are directly connected to each other without using the anisotropic conductive adhesive or in the case in which the connection wiring is formed after the peripheral circuit is transferred on the substrate with the adhesive, it is required to apply the necessary pressure evenly thereon in order for transferring the periphery circuit.